1. Field of the Invention
The present invention relates to a flow type ice making machine in which ice making water is frozen while the ice making water is flowing down over surfaces of a pair of ice making plates vertically disposed in back-to-back relation, and more particularly to an ice making unit structure of the ice making machine.
2. Description of the Related Art
In such a flow type ice making machine as one kind of automatic ice making machines, ice is made by supplying ice making water so as to flow down over surfaces of ice making plates which are cooled by utilizing the heat of evaporation of a coolant. A cooling zigzag pipe through which the coolant flows is disposed in contact with a back surface of the ice making plate. Generally, the cooling zigzag pipe is sandwiched between a pair of ice making plates vertically disposed in back-to-back relation (see, e.g., Japanese Utility Model Laid-Open No. 62-176669, Japanese Utility Model Publication Nos. 61-39262 and 1-24538, and Japanese Patent Publication No. 62-18820).
In the above-described structure, since the ice making plates are each formed of a thin metal material, the rigidity and the strength of the entire structure is given by a pair of mount plates for holding opposite bent ends of the cooling zigzag pipe and a body frame coupling the pair of mount plates to each other. Above the ice making plates, an ice making water sprinkler and an ice removing water sprinkler are disposed to extend in the direction of length of the machine between the pair of mount plates along the ice making plates. The ice making water sprinkler sprinkles ice making water over surfaces of the ice making plates facing outward in an ice making cycle, and the sprinkled ice making water flows down while contacting those surfaces of the ice making plates, i.e., ice making surfaces. On the other hand, the ice removing water sprinkler sprinkles ice removing water between the back surfaces of the pair of ice making plates in an ice removing cycle.
Positioning of the above sprinkler in the longitudinal direction (usually in the horizontal direction) may be effected by fitting the mount plates to grooves formed in respective side surfaces of the sprinkler's end portions, but this method requires a relatively long time for assembly work. Therefore, a structure for assembling the sprinkler by one-touch operation is previously proposed by the applicant and filed as Japanese Utility Model Application No. 5-34991.
The structure proposed will now be briefly described with reference to FIG. 7. Two pairs of ice making plates 2a, 2b are disposed side by side between a pair of mount brackets 1a, 1b, each pair of ice making plates 2a, 2b being arranged in back-to-back relation. Cooling zigzag pipes 3a, 3b extending between the two pairs of ice making plates 2a, 2b, respectively, are fixed to and supported by the mount brackets 1a, 1b. An ice removing water sprinkler 4 and an ice making water sprinkler 7 are combined and inserted to rectangular holes formed in upper portions of the mount brackets 1a, 1b. The ice removing water sprinkler 4 comprises two horizontal thin sprinkling tubes 5 extending parallel and integrally coupled to each other by a connecting portion 6, whereas the ice making water sprinkler 7 comprises two horizontal wide sprinkling tubes 8 extending parallel and integrally coupled to each other by a connecting portion 9. Further, positioning stoppers 8a, 8b are projected from respective outer side surfaces of the horizontal wide sprinkling tubes 8.
FIG. 8 is a plan view showing the ice making water sprinkler 7 in its fixed state. The stoppers 8a, 8b have grooves or slots formed therein to receive corresponding edges of the mount bracket 1a as shown. Specifically, the stoppers are designed such that when the sprinkler 7 is pushed in the direction of arrow A and reaches the illustrated position, the slots and the mount brackets 1a are engaged with each other as shown, thereby positioning and fixing the sprinkler 7.
In the above-described conventional structure wherein the sprinkler is positioned and fixed by fitting the mount plates to the grooves formed in the outer side surfaces of the sprinkler, if the grooves are not machined with good dimensional accuracy, it would be difficult to fit the mount plates to the grooves or, conversely, the sprinkler would wobble because of plays occurred therebetween.
Also, in the previously proposed structure wherein the sprinkler 7 is inserted to the rectangular holes in the mount plates or brackets and the grooves (slots) formed in the stoppers are engaged with the mount brackets, there arise problems below. It is general that, in the snap-fitting structure as shown in FIG. 8, the sprinkler 7 is formed of plastic to utilize elastic deformation of the stoppers 8a, 8b for snap-fitting. Accordingly, if a large error is caused in spacings between the stoppers 8a, 8b and between the rectangular holes, a serious problem would be resulted. For example, when the spacing M between the stopper slots is larger than the design size which corresponds to the spacing L between the rectangular holes, a tip end of the stopper 8b is shaven and turned up as shown in FIG. 9. Conversely, when the spacing M between the stopper slots is smaller than the design size, the stoppers 8a, 8b lose completely their functions of locking the sprinkler in place, or are so loose that the sprinkler is easily slipped off in the direction of arrow B in FIG. 8. One reason is that the plastic-made stopper 8a, 8b are relatively soft with respect to the metal-made mount plate 1a. Anyway, to solve the above drawbacks, manufacture accuracy of the relevant members must be remarkably improved, and a production cost is inevitably increased.
As an alternative means to solve the drawbacks mentioned above with reference to FIGS. 8 and 9, it would be conceivable, as shown in FIG. 10, to provide stoppers 8A, 8B which are extended in the opposite direction to the stoppers 8a, 8b shown in FIG. 9. In this case, too, the ice making unit cannot have an structure capable of accurately positioning the sprinkler with easy assembly, unless manufacture accuracy is improved.
More specifically, the ice making water sprinkler 7 is required to be positioned in the longitudinal direction such that sprinkling holes formed in a bottom wall of the sprinkling tube 8 are surely situated in predetermined positions with respect to the surfaces (ice making surfaces) of the ice making plates 2a and 2b. If the sprinkling holes of the sprinkling tube 8 are deviated from the predetermined positions with respect to the ice making plates 2a and 2b, the flows of the ice making water over the ice making surfaces would be changed to produce ice having an indefinite or deformed shape. Hence the quality of ice would be deteriorated and, in some cases, the ice machine would fail to remove the produced ice.
Likewise, the ice removing water sprinkler 4 must also be positioned such that sprinkling holes of the sprinkler 4 are situated in predetermined positions with respect to rear surfaces of the ice making plates 2a and 2b. If the positions of the sprinkling holes are deviated with respect to the ice-making plates 2a and 2b, the flows of the ice removing water would be changed, reducing the ice removing ability.
Further, if the ice making water sprinkler 7 and the ice removing water sprinkler 4 are overly projected in the direction of arrow B in FIG. 8, the water flow would overflow out of the ice making region, giving rise to a serious trouble.
Further, during the use for a long term, the interior of the sprinkler becomes dirty with deposition of the fur and impurities such as calcium and silicon contained in water. Though not shown in FIG. 8, it is therefore desirable to form a hole in, e.g., a distal end face of the sprinkling tube and to fit a cleaning plug to the hole, the plug being removed when the interior of the sprinkler is cleaned. The cleaning plug is a cone-shaped plug made of elastic material such as rubber, and is held in place by an elastic force developed at the time it is press-fitted to the hole formed in the sprinkling tube. However, when the ice machine is used for a long term, a reduction in the elastic force is inevitable and hence the cleaning plug may be so loosened as to cause leakage of water. On that occasion, if the sprinkler is loosely locked by the stoppers, there is a risk that the sprinkler may be pushed out in the direction of arrow B in FIG. 8 by water pressure. Finally, the cleaning plug is slipped off and water is scattered in all directions through the hole from which the cleaning plug has come out. This results in troubles that ice can no longer be manufactured and water is leaked.